The goal of this research is to develop an automated method of noninvasively imaging via fluoroscopy the diaphragmatic surface to directly measure its mechanical activity so that indirect quantitative measurements of tidal volume, air flow and overall pulmonary function can be performed. Characterization of diaphragmatic movement dynamics in the form of excursion amplitude and velocity measurements may be of vital importance in the assessment of respiratory function in man, and significant derivations from derived normalized group data may become an important indicator of abnormal pulmonary function in certain diseases. Other related areas of research include: 1. Evaluation of radiofrequency nerve stimulation (EPR) as a respiratory support technique in quadriplegics and adults with hypoventilation syndrome, chronic lung disease and sleep apnea. In this context initial development of suitable animal models in which EPR and diaphragm imaging are initiated during a variety of pulmonary system states will hopefully reveal the exact nature of the diaphragm's role in contributing to the maintenance of adequate ventilatory responses. This approach will then be evaluated in human studies. 2. Development of a mathematical computer simulation model for characterizing respiratory mechanical function using noninvasively derived data. Analysis of diaphragm movement dynamics will be accomplished by application of image processing techniques, to fluoroscopically derived television pictures of the entire thoracic cavity. This approach initially employed an electronic technique to automatically track and record the movement activity of the diaphragm edge projection as viewed during video recording. Subsequent application of this approach appears to be well-suited for complete digitization of the television picture for the facilitation of diaphragm image enhancement techniques. The application of image derived diaphragm movement and velocity information with other pertinent pulmonary function parameters could lead to an alternative noninvasive approach for evaluating pulmonary function, in vivo. Moreover, if noninvasive assessment of diaphragmatic activity proves to be an accurate predictor of pulmonary function, various therapeutic regimens may be evaluated in patients with chronic lung disease with minimal risk and discomfort.